Arrangement in masts for sailing-boats



Dec. 10, 1968 o. v. PLYM 3,415,215

ARRANGEMENT IN MASTS FOR SAILING-BOATS Filed Nov. 21, 1967 2 Sheets-Sheet l 05042 V/LHELM P4 YM lNVE/V'TOIQ.

Dec. 10, 1968 o. -v. PLYM ARRANGEMENT IN MASTS FOR SAILING-BOATS 2 Sheets-Sheet 2 Filed Nov. 21, 1967 lNl/ENTOR. M W 2% Fig. 3

0504 V/LHELM PL YM fl TTORNE X United States Patent 3,415,215 ARRANGEMENT IN MASTS FOR SAILING-BOATS Oscar Vilhelm Plym, Generalsvagen 131, Osterskar, Sweden Filed Nov. 21, 1967, Ser. No. 684,865 Claims priority, application Sweden, Nov. 25, 1966, 16,158/ 66 3 Claims. (Cl. 114-90) ABSTRACT OF THE DISCLOSURE A flexible mast having a lever means mounted on the top. This lever connects the fore and aft stays to the hull of the boat. The lever is pivotally connected to the mast.

This invention relates to an arrangement in masts for sailing boats.

It has long been usual to equip racing yachts and similar craft with masts which by bending impart correct aerodynamic shape to the sail in response to different wind strengths, and also impart correct angles to the sail with respect to the direction of the wind. As a general rule it can be said that in winds of moderate strength the sail should present a larger bunt than in the case of stronger winds. It is possible by flattening the sail to reduce the heeling moment, and the sail need not be reefed or taken in until meeting winds of higher strength.

It is relatively simple to bend the mast of a racing yacht or similar craft since generally the so-called foretriangle does not reach the top of the mast and it is consequently easy to obtain a bending moment in the mast.

The present invention is concerned with obtaining the same effect on a rig where the fore-stay is secured to the mast top. The arrangement according to the invention mainly comprises lever means secured to the mast top and extending in the longitudinal direction of the craft. The lever means is capable of pivoting around a substantially horizontal pivot and on one side of said pivot it has a long arm which is connected to the after-stay and a short arm connected on the other side of the pivot to the fore-stay. By varying the length of the arms it is possible to vary the direction of the resultant from the forces in the fore-stay and after-stay so as to either contribute towards the bending of the mast or become neutral or to counteract the said bending action.

When sailing it is most important that the fore-stay is properly stretched. Due to the bending of the mast the distance from the top of the mast to the deck will decrease; the effective length of the mast is equal to the chord of the curved bent mast.

Slackening of the fore-stay and after-stay, which would normally occur as the mast bends, is compensated by the fact that the back-arm is longer than the fore-arm and in this way the stretch in the forestay and after-stay will be retained. The length of the arms can also be adjusted so that the tension in the stays will increase or decrease when the mast bends.

The mast is bent by the action of the Wind on the sail and the force in the sheet, which will influence the mast through the sail. Bending of the mast can also be caused by means of an auxiliary after-stay, secured to the mast or by attaching the topping lift to the after-deck and tightening the same. This arrangement may also be used to dampen or subdue movements of the mast in high seas. The desired resistance to bending can be obtained by varying the length of the arms, as previously disclosed.

An embodiment of an arrangement according to the invention is shown as an example in the accompanying drawing, wherein:

FIGURE 1 shows a sailing boat in side view,

FIGURE 2 shows on a larger scale the top portion of mast and FIGURE 3 is a diagrammatic view of the arrangement according to the invention, seen in the longitudinal direction of the craft.

The top of the mast 1 of the sailing boat is equipped with lever means or balancing means 3 pivotable about a pivot 2 and extending in the direction of the fore-andaft axis of the craft. The arm 3a of the lever 3 located in front of the pivot 2 is shorted than arm 31; located aft of said pivot. The fore-stay is fastened to arm 3a while the after-stay 5 is secured to arm 3b. When the mast 1 is preferably upright (fall lines in FIGURES 1 and 2) the lever means is shown in the figure as occupying a horizontal position. This position can be varied so that the movement will be suflicient to achieve the desired degree of bending.

When the mast bends towards the stern of the vessel (dash lines) the arm 3a will swing downwards and arm 312 will swing upwards. Bending of the mast causes the mainsail 6 to flow or bunt at its front edge to an advantageous degree. By bending the mast it is possible to vary the degree of flow or bunt of the sail so that the said sail can be caused to flow to the desired extent in different wind conditions.

FIGURES 2 and 3 illustrate how the lever means 3 is secured to the mast top by means of a fitting 7 having a U-shaped stirrup member 8 in which the pivot 2 is mounted. The lever 3 may also be U-shaped. A pulley 9 may be mounted on pivot 2, for the mainsail halyard and topping lift. Securing flanges 10 for the shrouds 11 may be mounted to the fitting 7 for rotation.

The foresail halyard 12 may run over a pulley 13 in a link 14 which is at one end connected to the foresail stay 4 and at the other end is pivotally connected to the arm 3a. Alternatively the foresail halyard can run over a pulley at the outer end of arm 3a and further over any one of the pulleys 9.

The lever 3 may also be in the form of a chain or wire passed over a wheel, or comprise an eccentric wheel or the like. The lever 3 may also be provided with stop means which restrict the rotary movements thereof, to limit the extent to which the mast can be bent.

What I claim is:

1. An arrangement in sailing boats or crafts having a flexible mast with fore-stay and after-stay secured to the top of the mast, lever means secured at the top of said mast and extending in the direction of the fore-and-aft axis of the craft said lever means being pivotable about a substantially horizontal pivot and comprising a long arm located at one side of the pivot and connected to the afterstay and a short arm located at the other side of the pivot and secured to the fore-stay.

2. An arrangement according to claim 1 wherein the lever means comprises a pivotable balance arm.

3. An arrangement according to claim 1, wherein the lever means is mounted to a fitting secured at the top of the mast said fitting comprising pulleys for the sail-halyards.

References Cited UNITED STATES PATENTS 2,162,441 6/1939 Mead 11439 MILTON BUCHLER, Primary Examiner.

T. M. BLIX, Assistant Examiner. 

